Self-latching hinge

ABSTRACT

A device for a concealed twin-linked hinge suitable to automatically block a door, flap door or horizontally bowed door at its closed position, wherein the device is comprising a resilient member, secured to a stationary part of the hinge, and one or two cams acted upon by said member and pertaining to one of the movable elements of the hinge, particularly to the innermost of the two links forming one of the oscillating rods for the twin-linked hinge system.

United States Patent Luciano Saliee Cantu, ltaly Nov. 20, 1967 July 6, 197 1 Arturo Salice S.p.A.

Cantu, Italy Nov. 21, 1966, Oct. 6,1967 ltaly 30192A/66 and 21332A/67 inventor Appl. No. Filed Patented Assignee Priority SELF-LATCHING HINGE 21 Claims, 35 Drawing Figs.

us. Cl

Field of Search 16/164, 16/145 Int. Cl E0511 3/06 16/164, 163, 145

[56] References Cited UNITED STATES PATENTS 2,623,236 12/1952 Borchers et a1 16/135 2,940,116 6/1960 Salice 16/190 X 3,363,281 1/1968 Borsani 16/163 FOREIGN PATENTS 1,044,898 10/1966 Great Britain 16/163 Primary Examiner-Bobby R. Gay Assistant Examiner-Peter A. Aschenbrenner Attorney-Krafi't and Wells ABSTRACT: A device for a concealed twin-linked hinge suitable to automatically block a door, flap door or horizontally bowed door at its closed position, wherein the device is comprising a resilient member, secured to a stationary part of the hinge, and one or two cams acted upon by said member and pertaining to one of the movable elements of the hinge, particularly to the innermost of the two links forming one of the oscillating rods for the twin-linked hinge system.

PATENTEDJUL 6197i 3,590,420

SHEET 1 OF 3 INVENT( )R Luciano SAL g ATTORNEYS PATENTEDJUL SIBYI $590,420

SHEET 2 0F 3 INVENTOR Luciana SAL/CL ATTORNEYS PATENTED JUL 6l97| 3, 590,420

sum 3 [1F 3 INVENTOR Luciana SAL ICE BY WV 111% SELF-LATCI-IING HINGE The present invention relates to concealed twin-linked hinges enabling doors, flap doors or horizontally bowed doors, and particularly cabinet doors (all hereinafter called doors) to be hingedly mounted on stationary frames.

The principal object of this invention is a device for hinges of the above mentioned type, as well as a hinge of this type comprising the said device.

Generally, using a pair of twin-linked hinges of the known type, it is necessary to use also one or more latches to block the doors provided with hinges, in the closed position.

It is therefore one object of this invention to provide a device which can be incorporated in a hinge of such type and which gives the same effect that normally can be obtained by means of an additional latch.

The device according to this invention allows a free rotation of the movable element of the hinge with regard to the stationaryone, and that on its whole are of revolution, with the exception of a short final section near the closing position, in which section the device itself pushes strongly the said movable element towards the closing position, where it maintains it then with strength.

Another object of this invention is to provide a concealed twin-linked hinge comprising such a device.

Using the hinge according to this invention there is therefore the advantage that it is no longer necessary to apply the Latch which generally goes together with the hinges and this brings a sensible economy, not only because the cost of one part can be saved, but also because the work for its application and its adjustment can be saved.

Besides it might be expected, for one or more reasons well known by the people of the branch, that after a period of use the door would no longer have its inner surface flush with the base of the frame, the result is that the latch is no more harmonizing with the corresponding counterpart and this may cause the missed hooking or worse, as impediment for the closing of the door.

It is evident that the device according tothis invention, for the reason that it is incorporated into the hinge, eliminates also the possibility of this inconvenience.

Further advantages and characteristics of the device according to this invention will clearly result from the following description about some of its features of construction and arrangement of parts, given only as examples and not limitative, with reference to the accompanying drawings, wherein:

FIG. 1 is a cross section provided with a self-latching device according to this invention, where the arrangement of its components is seen in case of open doors.

FIG. 2 is a view similar to FIG. 1, with the hinge in the closed door position.

FIGS. 3, 4 and 5 are three views of a first feature of construction of the devices spring, of the little roller associated to the spring, and also of the mode of coupling such a spring with the stationary element of the hinge.

FIGS. 6 and 7 are a top view and a side view of a second feature of construction of such a spring and of the associated little roller.

FIGS. 8, 9, 10, 11 and 12 are top and side views of a third feature of construction of such a spring and of the associated little roller.

FIGS. 13 and 14 are a top view and a side view of a fourth feature of construction of the spring which acts in this case directly without interposition of the little roller.

FIGS. 15 and 16 are perspective views of a fifth feature of construction of the spring and of the associated little roller.

FIG. 17 is a perspective view of a first feature of construction of the inner link which'is a component of the device.

FIGS. 18, 19 and 20 are perspective views of other three different features of construction of such a link.

FIG. 21 is a perspective view of the stationary element of the hinge.

FIG. 22 is a perspective view of a spring provided with a small roller.

FIG. 23 is a perspective view of a base of the hinge.

FIG. 24 is a perspective view of a subbase. I

FIG. 25 is a perspective view of a further spring having a smaller roller.

FIGS. 26 and 29 are perspective views of small rollers of a different structure.

FIG. 27 is a perspective view of the small roller of FIG. 6, as cut into two halves according to a diametrical plane.

FIG. 28 is a perspective view'similar to that of FIG. 7 showing a further small roller.

FIG. 30 is a partially sectional side view showing a hinge as completed with an auxiliary spring.

FIG. 31 is a perspective view of the stationary element of the hinge having an auxiliary cup spring.

FIGS. 32 and 33 are plan and side views, respectively, of a composite spring.

FIG. 34 is a partially sectional side view according to line 14-14 of FIG. 1 of the stationary element of the hinge, as completed with base and subbase.

FIG. 35 is a sectional view showing a structural detail as well as an axial section of the movable portion.

FIGS. 1 and 2 are sectional views of a hinge provided with the device according to this invention, once in open position, once in closed position.

It is to say that many components of the illustrated hinge are known and are not an object of the present invention. These components have been illustrated only for a better understanding of the device according to this invention. A detailed description will however be given only about the device according to this invention, from which the characteristics will clearly result.

In these figures are illustrated and marked with l and with 2 respectively, the ends of the stationary frame and of the doors fixed in twin-linked manner by means of the hinge comprising the device according to this invention.

Such a hinge includes a base 3 previously fixed, i.e. by means of screws 4 on the stationary frame 1. It is to note that such a base can have alternatively the form marked in FIG. 2 with 5; in this case the base 5 is fixed on the stationary frame 1 through fish-bone shaped (6a) cylindrical portions 6 which assure a firm holding in the slots Ia elaborated in the stationary frame 1 itself.

A stationary element 7, preferably with a U-shaped cross section, is secured to the base 3 (or 5) by means of a screw 8. A regulating screw 9 is screwed up in a threaded hole of the stationary element 7 and its end leans directly or indirectly upon the base 3 (or 5). In this way, screwing up more or less the regulating screw 9, the element 7 removes more or less from the stationary frame 1 and in this way also the alignment of the doors (2) edge with the stationary frame 1 can be adjusted. Once such an adjustment is finished, the stationary element 7 may eventually be blocked in its position with regard to the frame 1 by means of the screw 10.

The stationary element 7 is pivotally fixed by means of the pivots 11 and 12 with regard to the movable part 13 of the hinge, which can be fixed in the cylindrical cavity 14 of the door by means of screws 15. In alternative, the said movable part can assume the form designated 16 in FIG. 2 and, more precisely, present the fish-bone shaped threading 17 which assures the holding in the cavity 14 without using any other screws.

On the movable element 13 (or 16) are firmly fixed two pivots l8 and 19 which eventually can be the two arms of a sole U-shaped piece. The outer link of the joint which is designated 20, is arc-shaped and ends with two eyelets which embrace respectively the stationary pivot 11 and the movable one 19; around these pivots the link 20 can freely oscillate.

All said above about the chief and known parts of the hinge comprising the device according to the present invention has been mentioned for the purpose of a better understanding of the following description about the device itself.

Such device comprises a resilient member which is fixed on a stationary part of the hinge, and one or two cams, upon which such member acts and which belong to one of the movable elements of the hinge, especially to the inner one of the two links which represents one of the oscillating bars of the twin-linked hinge system. Such link is marked with 21 in the figure. Said resilient member consists of a spring which can be inserted under stress in the stationary element of the hinge so that one of its end is fixed on the said element's end which is further from the hingedly mounted axis, while its middle part touches the back wall of such element and its other end is engaged with one or two cams.

The link 21 FIGS. 1, 2 and 17) is known on its whole for the kinematics of the joint which realizes together with the link 20 through its curled knuckles 23 and 22 which embrace the pivots 12 and 18.

A completely new and essential element of the device according to the present invention is however the cam 25 obtained by bending in a different way one section of the curled knuckle 23 with which the link 21 includes the pivot 12 which is carried by the stationary element in the part that lays nearest to the hingedly mounted axis; in connection with such cam 25 a little window 24 is formed.

It is to note that the term cam" means a-bent portion as explained above, of the curled knuckle 23 of the link 21.

This term is used for a formal analogy with the known cams; however, in this case, the function results inverted. Indeed, in the devices with ca'ms of the known type, the cam is the moving part while the tappet associated to it is the part which gives way; in the present case, however, the cam 25 is the part that gives way, under the addition of the tappet which consists, as it will be explained later on, of the spring provided eventually with a little roller.

The said cam 25 presents, as shown in FIG. 35, a bent section 25a with constant radius and, near to its outer edge, a section with variable and in preference growing radius 25b which function will be explained later on.

The spring as a part of the device according to this invention may have different features of construction. One of these and namely the first one is designated 30 in the FIGS. 1, 2, 3 and 4. These figures show that the spring 30 is a spring subjected to bending, made of a thin metallic substantially U-shaped rod, whose arms end with the outward bent stubs 33, which are adapted to penetrate into slots 34 with which the outermost end of the stationary element is provided.

On its other end the spring 30 is provided with two inward bent zones and a rectilinear section 32 which is almost per pendicular to the arms 30 and around which turns a little hollow roller 31, preferably made of steel; the said hollow little roller is centered thanks to the bent zones 32, with regard to the spring. Each arm of the spring 30 has an arcuated form in the resting position; consequently the spring 30, when it is put into the element 7, so that it leans with the convex part of such arms against the plain back wall of said element, is under load.

The said load is transmitted through the little roller 31 on the cam 25 of the link 21. It results that the stationary element 7 and in general the whole stationary part of the hinge is elastically linked through the spring 30 and the little roller 31 with the movable part.

The function of the above described device and more generally of the hinge comprising it, is the following:

As FIG. 1 clearly shows, in the open door positionthe little roller 31 leans against the cam 25. During the closing of the door 2, after which the door takes the position shown in FIG. 2, the little roller 31 runs along the cam 25, and this is because the link 21 moves turning at the same time around the pivot 18.

For a great part of its run, thanks to the form of the cam, which presents a section with constant radius 25a, the little roller 31 keeps a constant distance from the axis of the pivot 12, so that the spring 30 does not exchange work with the link 21 while the latter is oscillating; for this reason the rotation of the movable part of the hinge with regard to the stationary one (and therefore the door with regard to the frame) is completely free. But towards the end of the rotation of the door and therefore towards the end of the sliding of the little roller 31 along the cam 25, after the curving with growing radius 2512, the spring 30 is still in action and therefore the rotation results more difficult. Finally the little roller 31 overtakes the outer edge of the cam 25 and, under the action of the spring 30, penetrates with a click into the little window 24. Therefore also the door 2 closes with a click and remains firmly blocked in the closed position. Like that it is not necessary to mount a latch or something similar on the door. Indeed, the opening of the door requires a considerable effort in the first opening phase in order to release the little roller 31 from the little window 24 and to bring it back on the cam 25 by conquering the action of the spring 30. Once this happens, the remaining rotation of the door ensues freely because also the little roller 31 slides freely along such cam.

Considering the above mentioned essential constructive principles as well as the functional ones, we describe now other features of construction of the device according to this invention.

According to the feature of construction of FIGS. 6 and 7, also the spring 35 is made of a thin metallic rod and in top section is U-shaped, with arms which are, seen sideways, bent and form right angles with the connecting tract 35 which carries the little roller 36; the latter one has two lateral prolongations 37 having the form of a coupling sleeve and aim at holding centered the little roller itself with regard to the spring 35 and therefore with regard to the cam 25.

According to a third feature of construction shown in FIGS. 8, 10, 111 and 12 the spring 38, made of a thin metallic rod, has in top section a substantially rectangular form, whose longer sides, if seen sideways, are bent; the two free ends 39 of such a spring form one of the short sides of the rectangular spring and fit exactly together in harmony with the middle part of the little roller 36.

It is to say that in this case (see FIG. 12) the spring 38 is hooked up on the stationary element 7 be means of a curled lug end 40 elaborated on the end of the stationary element and bent like a hook.

In FIGS. 113 and 14 is represented a spring 50 analogous to the spring 30which arms 51 in Harmony with the end of the spring acting upon the cam 25 of the link 21 present approached little portions 52 which, seen sideways, are bent like an arc. For their whole remaining length said arms are, seen sideways, arc-shaped with a curvature being opposed to the one of the little portion 52. Finally each of said arms finishes on the opposed end with a stub 53 sticking outwards in order to be plugged in a slot 34 of the stationary element 7.

It is obvious that in this case the bent approached little portions 52 have the same function, with respect to the cam 25, as the little roller 31, which is therefore omitted. During the functioning there will be only a sliding friction instead of a rolling friction.

In the above-described features of construction the spring is expected to be made of a thin metallic rod. As a variant shown in FIG. 15 the said spring marked with 41 is, on the contrary, made of steel-sheet. The spring 41 presents on one end a central window 42 enabling the little roller 43 (FIG. 16) to be taken in, as well as two curled lugs 44 enabling the axial side stubs 45 of the little roller 413 to be lodged. The other end of the spring 41 is bent on itself in 46 in order to lodge a pivot 47 whose ends penetrate in the slots 34 of the stationary element 7.

In all the above described features of construction the spring, with the associated little roller, forms an organic part corresponding with the tappet associated to a cam excepting the fact, as mentioned above, that the functions are inverted. A tappet of a known type generally comprises several parts which all have a well determined function, and that strictly speaking: a bar which eventually is provided with a little roller to receive the motion; a prismatical or cylindrical couple which guides it in its motion and a resilient member ensuring the contact with the cam. On the contrary, in the present case, the three above said functions are carried out simultaneously and efficaciously by only one piece which is easy to realize, and that by the spring.

The construction is therefore very simplified and that means a lower cost of production, an easier assembly and a higher operating safety.

FIG. 18 shows another feature of construction of the inner link, which is now marked with 26 and which can take, on the whole of the hinge, the place of the link 21.

According to this feature of construction, instead of only one central cam 25, in harmony with the bent ends 23, there are two lateral ones (27 and 28) similar to the above mentioned cam 25. In harmony with such earns 27 and 28 there are the opening 29.

Obviously, in this case, the spring 30 (or 35 or 38) will have two little rollers instead of only one, adapted to be engaged respectively with the cams 27 and 28 and with the openings 29 in analogous way to what described about the cam 25 and the little window 24.

In the above described features of construction 21 and 26 the inner link is expected to be made of pressed metallic sheet.

FIG. 19 is another feature of construction of the said inner link, which is now marked with 55 and which can take, on the whole of the hinge, the place of the links 21 or 26.

According to this feature of construction the link 55 consists of a full piece obtained either by hot-pressing or melting or sintering. In this case, the cam consists of a groove 56 and of a lug 57 and the link 55 is also provided with a cavity 58 similar to the window 24 of the link 21.

FIG. 20 is still another feature of construction of the said inner link, which is now marked with 60 and on the whole of the hinge can take the place of the links 21 or 26 or 55.

According to this feature of construction the link 60 consists of a packet of iron sheets 61 shared and placed side by side. The central iron sheets 61a of such packet have their ends moulded so as to form the cam 62 wholly similar to the cam 25 as well as the concavity 63 wholly similar to the window 24 of the link 21.

In the above described embodiments the resilient element was always formed of one spring only; However, the present invention contemplates the insertion of one or more auxiliary springs in the device.

Indeed, both for aesthetical and functional requirements, the hinge comprising any of the above described devices should be compact and therefore the space available therein for the resilient element (spring) is little On the other hand, for providing an efficient closing the spring should be capable of storing a substantial amount of elastic energy.

In order to increase the spring storing capability without a substantial increase in the overall size, this invention contemplates the provision for one or more auxiliary springs, in series with the mainspring, which are of a minimum size and suitable to utilize the little available space in the best possible way.

Thus, a more active hooking action of the device can be obtained without size increasing.

FIGS. 29, 30, 31, 32 and 33 show how such auxiliary springs are provided and mounted. Referring particularly to FIG. 30, the auxiliary leaf spring 141 is inserted between the bottom of the movable element 7 and the main spring'30.

In FIG. 31 the auxiliary spring is formed of one or more cup springs 151 threaded about collar 9 acting as a nut screw for the adjusting screw 9, already described in FIGS. 1 and 2.

In FIGS. 32 and 33 there is shown a further embodiment of the auxiliary flexure spring 161, formed of two leaf springs 162 and 163 of a varying width so as to approach the shape of the uniform flexural strength solid, interconnected by two crosspieces 164 and 165 enabling said two leaf springs 162 and 163 to be integrally manufactured and concomitantly allowing a ready handling and anchoring thereof about a projection of the stationary element of the hinge, such as collar 9'.

In operation, as the two springs-the mainspring 30 or the like, and the auxiliary spring 141 or the Iikeare serially arranged, they will be subjected to the same flexural strength, but sharing the stroke at the rate of the flexibility thereof, so that even the elastic energy as stored or restored by the system of the two springs will be the sum of those as stored or restored from the two springs separately.

As above stated, said one or more small rollers forming part of the device are metal rollers.

Following the description already made for some embodiments thereof, further embodiments will be hereinafter described which are of a particularly ready manufacture and application. I

Such small rollers are shown in FIGS. 2529. More particularly, in FIG. 25 there is shown a spring 110, similar to the already described springs 30 and 35, wherein a small roller 111 is about the shortest intermediate side 112 as shown in FIGS. 26, 27 and 28, such a small roller was provided by rolling a wire as a cylindrical spiral; when made separately, the ends thereof may be rectified, thus obtaining a configuration exactly inscribed within a right circular cylinder.

FIG. 28 shows a helical small roller of an entirely cylindrical form, as obtained by winding a wire or a metal rectangular section strap in more or less closed turns.

Each of the just described small rollers show the advantage that, even when having to be mounted on a continuous side of the spring, as defined by two right angle folds hindering the threading for a whole small roller such as that which may be obtained, for instance, by turning a drawn bar, a helical wire small roller can be directly wound onto said side, or separately wound and then forcibly threaded, by taking advantage of the flexibility inherent to the material of which it is formed.

FIG. 29 shows a small roller 131 as obtained by approach of metal sheet. It may be prepared with its connection quite retracted for the passage of the spring wire and its closing may be completed on said spring with an obvious manufacture simplification.

Although the small rollers are generally provided as metal rollers, it is contemplated in this invention that they may be as well of any other suitable material, such as plastic material. In the latter case, the small roller may possibly have on its outer and/or inner surface, where a hollow small roller is involved, a metal tubular armature.

As said above, a hinge comprising the above described device, in several features of construction, is also an object of the present invention.

In the preferred feature of construction of the above described hinge which is illustrated in FIG. 1 and 2, the stationary element 7 comprises the device according to this invention.

However, when the hinge is provided with a base preapplied to the frame to which the door is hinged, the device as described is not applicable to said base, in the usual case wherein the hinge is adjustably attached to said base; indeed, during the linear and angular excursions by which the attitude of the revolving door can be adjusted, as desired, with respect to the stationary frame, the mutual position of the spring fast with said base would be changed relatively to the cam rocking lever forming part of the actual hinge, and as a result the hooking action of the spring would vary with the hinge adjustment in an accidental and not admissible way.

Therefore, according to a further embodiment of this invention the elastic member (spring) of the device is provided as accommodated within a fixed base, in place of being directly located within the hinge.

The base accommodating the device is rendered fast with the hinge, whereas the hinge and its base can be adjusted at their position: directly, with respect to the cabinet frame, or indirectly, through a subbase preattached to said frame.

The following advantages would result: Capability for adjusting the position of the hinge relative to the cabinet and thus of the'door relative to the frame to which it is hinged, without varying the operation for the hooking device. Capability for attaching the hinge directly to the cabinet, without using a base preattached thereto, or, as desired, the capability for using an auxiliary base preattached to the cabinet. Easiness for mounting the spring in the proper base and mounting the latter in the stationary element of the hinge.

In FIG. 21 there is shown a stationary element 70 of the concealed linked hinge, entirely similar to that indicated at 7 in FIGS. 1, 2, and 12, with the addition ofa tab 71 having its end 75 bent at right angles and suitable to ensure a base for said stationary element. I

In FIG. 22 there is shown a spring 80 provided with a small roller 81 inserted in one of the short sides 82 thereof and having a joint the short side 84 opposite to the small roller; said spring is entirely similar to springs 30 and 35 and particularly spring 38 of FIGS. 4, 6-7 and 8-9, respectively.

Depending on manufacture convenience, said joint may be on side 82 within the small roller 81 aiding to the mounting thereof, similarly to joint 39 for spring 38 of FIG. 8.

In FIG. 23 there is shown the base 90 for the hinge, in which there are seen: the bearing 91 comprising a plane as inclined as the bottom of said element which the preloaded spring will urge against the inner bottom of the stationary element 70, thus ensuring the solidarity for the two elements 70 and 90; the undercutting 92 for the passage of an adjusting screw; the oval window 93, through which a clamping screw for the hinge can pass; the semicylindrical seating 94 for the short side of the spring opposite to the side carrying the small roller; the two curved shoulders 95 acted against by the two long sides 83 of the spring; the two rims 96 distributing the bearing for the hinge on the cabinet frame and concealing spring 80 from view.

In FIG. 24 there is shown the eventual subbase 100 adapted to be preattached to the stationary frame for the door; said subbase is comprised of a plate having two longitudinal shoulders serving the triple purpose of stiffening said plate, guiding the hinge overlying thereon in its longitudinal adjustment, and concealing the inner portions of the hinge; the two or more preferably counterbored holes 102 are for accommodating two.or more screws or similar connecting means, by which said plate 100 is to be preattached to the door frame (such as a cabinet sidewall); the threaded hole 103 acts as a nut screw for the hinge anchoring screw; the indents 104 are intended to match with the relative teeth 74 for the stationary element 70 of the hinge.

As from FIG. 34, the spring 80 bears its short side or leg 84 within the groove 94 of base 90 and its long sides or legs 83 under the two shoulders 95 of said base; its small roller 81 transfers the load of the spring against the cam or earns 25 of the rocking lever 21, or the like. By its square fold 75, said tab 71 grasps said plate 90, inserting within the proper seating 97 of the latter. Thus, the hinge, spring and base form a unit assembly capable of operating independently of its adjustment with respect to the door frame, to which it will be next applied. The operation of the assembly is completely equivalent to that already described in connection with the embodiment of FIGS. 1 and 2. The hinge can be secured directly to the frame by a screw passing through the oblong holes 73 and 93, which allow for an adjustment along the length of the hinge, whereas another screw associated with the threaded hole 72, passing through the undercutting 92 and bearing its end on the bottom thereof, may operate for adjusting said hinge according to a direction at right angles to the preceding one. When using the plate or subbase to be preattached to the door frame by two screws passing through the holes 102, a metal screw introduced through the oblong holes 73 and 93, will engage within the threaded hole 103, thus allowing said hinge to be anchored to subbase 100. The oblong holes will allow said hinge and the base thereof to slide along said subbase 100, while teeth 74 of the hinge, when said anchoring screw has been tightened, will avoid any further longitudinal movement of the hinge on the stationary frame and any further and even casual operation of the adjusting screw passing through holes 72 and 92, by engaging within the toothing 104 of said subbase.

It is to say that also with very little variant, the effect caused by the action of the spring can be graduated as desired, with the form of the cam (of of the cams) and/or the mutual position of the associated little roller (or of the associated little rollers).

It stands to reason that further modifications and variants the links, characterized in that said resilient member is an arched bridge, one end of which urges the farthest end of the stationary part of the hinge while the other end urges a cam means carried by the innermost of the links, said cam means having a constant radius bent section and a varying radius bent section adjacent its extreme edge.

2. A device according to claim 1 wherein said resilient member is a flexural spring made of a U-shaped thin metal rod.

3. A device according to claim 1 wherein said arched bridge is formed by a flexural spring metal rod which is of a substantially U-shape, the arms of which have, at the end of the spring means to act on the cam, approached sections bent in ac cordance with a circular arch, while for all the remaining length thereof, they show an arched shape, the curvature of which is opposite to the former and finally, terminating each at the opposite end with an outward projecting extension adapted to be inserted in a hole pertaining to the stationary element. I

4. A device according to claim 3, wherein said spring is of a substantially U-shaped form, the legs of which have at the end of the spring adapted to act upon the cam means closely spaced apart sections according to a circle arc, while for the remaining length thereof has an arcuate shape, the curvature of which is opposite to the former and, finally, terminating each at the opposite end with an outward projecting extension adapted to be inserted in a hole of the stationary element.

5. A device according to claim 3, in which said arched bridge is formed of a thin metal resilient rod adapted to be inserted under load in the'stationary element of the hinge, so that an end thereof is secured to the farthest end of said element from the pivoting pin, whereas the median portion thereof contacts the bottom wall of said element and the other end thereof is engaged with said cam means through a small roller.

6. A device according to claim 5, wherein said arched bridge is of a substantially U-shape, each of the legs of which have adjacent the joint section thereof carrying said small roller on inward bending and terminating at the opposite ends thereof with an outward projecting extension suitable to be insorted in a hole of said stationary element, said legs having an arcuate shape.

7. A device according to claim 6, wherein said resilient bridge is of a substantially U-shape, the legs of which spring being at right angles to the joint section thereof carrying said small roller and each of which legs having at the opposite end thereof an outward projecting extension suitable to be inserted in a hole of said stationary element, said legs having an arcuate shape.

8. A device according to claim 3, wherein said resilient bridge is of a substantially rectangular section, the long sides of said rectangle being arcuate and having the two free ends thereof forming one of the short slides of said rectangle and matching to each other at the median portion of said small roller.

9. A device according to claim 1, in which the resilient bridge is formed of a steel coil spring at one end having aperture means being adapted "to accommodate a small roller forming part of said resilient bridge and some bent over tabs adapted to accommodate the axial side projections of said roller means, said spring being adapted to be inserted under load in said stationary element of the hinge, so that an end thereof is secured to the farthest end of said stationary element from the pivoting pin, whereas the median portion thereof contacts the bottom wall of said element and the other end thereof is engaged with said cam means through said roller means, said cam means having a constant radius bent section and a varying, preferably increasing, radius bent section adjacent to its extreme edge.

10. A device according to claim 5, wherein said small roller is hollow.

l l. A device according to claim 5, wherein said small roller has two side sleevelike projections.

12. A device according to claim 5, wherein said cylindrical small roller is provided with winding up a wire.

13. A device according to claim 5, wherein said small roller is provided with metal plate curling.

14. A device according to claim 1, wherein said arched bridge urges the stationary part through a base, adjustably fitting, to the stationary part of the hinge, said arched bridge having the other end thereof engaged with said cam means.

15. A device according to claim 14, wherein said base accommodating said arched bridge is connected with the stationary part of the hinge through a subbase provided with means for fastening thereof to the frame relative to which said door is to be hinged, and adjustable coupling means to said stationary part of said hinge.

16. A device according to claim 1, wherein said arched bridge is inserted under load within the stationary element of the hinge, so that an end thereof is secured to the farthest end of said element from the pivoting pin, whereas the median portion thereof contacts the bottom wall of said element and the other end thereof is engaged with said one or two cams, further auxiliary spring means serially connected being inserted for increasing the pressure of the resilient bridge on the cam means.

17. A device according to claim 16, wherein the auxiliary springs are cup springs threaded into a projection in the stationary part of the hinge.

18. A device according to claim 16, wherein the auxiliary springs are flexural leaf springs interconnected by ties,

adapted to be accommodated within the inner projections of said stationary part of the hinge.

19. A hinge according to claim 1, wherein the link having said cam means is made of pressed metal sheet.

20. A hinge according to claim 1, wherein the link having said cam means is of molded metal obtained by hot-pressing, die casting and sintering.

21. A hinge according to claim 1, wherein the link having said cam means is formed of a packet of sheared iron sheets arranged in a side-by-side relationship. 

1. A device for an articulated, concealed hinge adapted to automatically block in its closed position, a door, a flap door or a flap table, the hinge including two links, one of which is in the outermost position while the other link is in the innermost position, and comprising a resilient member interposed between the stationary part of the hinge and the innermost of the links, characterized in that said resilient member is an arched bridge, one end of which urges the farthest end of the stationary part of the hinge while the other end urges a cam means carried by the innermost of the links, said cam means having a constant radius bent section and a varying radius bent section adjacent its extreme edge.
 2. A device according to claim 1 wherein said resilient member is a flexural spring made of a U-shaped thin metal rod.
 3. A device according to claim 1 wherein said arched bridge is formed by a flexural spring metal rod which is of a substantially U-shape, the arms of which have, at the end of the spring means to act on the cam, approached sections bent in accordance with a circular arch, while for all the remaining length thereof, they show an arched shape, the curvature of which is opposite to the former and finally, terminating each at the opposite end with an outward projecting extension adapted to be inserted in a hole pertaining to the stationary element.
 4. A device according to claim 3, wherein said spring is of a substantially U-shaped form, thE legs of which have at the end of the spring adapted to act upon the cam means closely spaced apart sections according to a circle arc, while for the remaining length thereof has an arcuate shape, the curvature of which is opposite to the former and, finally, terminating each at the opposite end with an outward projecting extension adapted to be inserted in a hole of the stationary element.
 5. A device according to claim 3, in which said arched bridge is formed of a thin metal resilient rod adapted to be inserted under load in the stationary element of the hinge, so that an end thereof is secured to the farthest end of said element from the pivoting pin, whereas the median portion thereof contacts the bottom wall of said element and the other end thereof is engaged with said cam means through a small roller.
 6. A device according to claim 5, wherein said arched bridge is of a substantially U-shape, each of the legs of which have adjacent the joint section thereof carrying said small roller on inward bending and terminating at the opposite ends thereof with an outward projecting extension suitable to be inserted in a hole of said stationary element, said legs having an arcuate shape.
 7. A device according to claim 6, wherein said resilient bridge is of a substantially U-shape, the legs of which spring being at right angles to the joint section thereof carrying said small roller and each of which legs having at the opposite end thereof an outward projecting extension suitable to be inserted in a hole of said stationary element, said legs having an arcuate shape.
 8. A device according to claim 3, wherein said resilient bridge is of a substantially rectangular section, the long sides of said rectangle being arcuate and having the two free ends thereof forming one of the short slides of said rectangle and matching to each other at the median portion of said small roller.
 9. A device according to claim 1, in which the resilient bridge is formed of a steel coil spring at one end having aperture means being adapted to accommodate a small roller forming part of said resilient bridge and some bent over tabs adapted to accommodate the axial side projections of said roller means, said spring being adapted to be inserted under load in said stationary element of the hinge, so that an end thereof is secured to the farthest end of said stationary element from the pivoting pin, whereas the median portion thereof contacts the bottom wall of said element and the other end thereof is engaged with said cam means through said roller means, said cam means having a constant radius bent section and a varying, preferably increasing, radius bent section adjacent to its extreme edge.
 10. A device according to claim 5, wherein said small roller is hollow.
 11. A device according to claim 5, wherein said small roller has two side sleevelike projections.
 12. A device according to claim 5, wherein said cylindrical small roller is provided with winding up a wire.
 13. A device according to claim 5, wherein said small roller is provided with metal plate curling.
 14. A device according to claim 1, wherein said arched bridge urges the stationary part through a base, adjustably fitting, to the stationary part of the hinge, said arched bridge having the other end thereof engaged with said cam means.
 15. A device according to claim 14, wherein said base accommodating said arched bridge is connected with the stationary part of the hinge through a subbase provided with means for fastening thereof to the frame relative to which said door is to be hinged, and adjustable coupling means to said stationary part of said hinge.
 16. A device according to claim 1, wherein said arched bridge is inserted under load within the stationary element of the hinge, so that an end thereof is secured to the farthest end of said element from the pivoting pin, whereas the median portion thereof contacts the bottom wall of said element and the other end thereof is engaged with said one or two cams, further auxiliary spring means serially connected being inserted for increasing the pressure of the resilient bridge on the cam means.
 17. A device according to claim 16, wherein the auxiliary springs are cup springs threaded into a projection in the stationary part of the hinge.
 18. A device according to claim 16, wherein the auxiliary springs are flexural leaf springs interconnected by ties, adapted to be accommodated within the inner projections of said stationary part of the hinge.
 19. A hinge according to claim 1, wherein the link having said cam means is made of pressed metal sheet.
 20. A hinge according to claim 1, wherein the link having said cam means is of molded metal obtained by hot-pressing, die casting and sintering.
 21. A hinge according to claim 1, wherein the link having said cam means is formed of a packet of sheared iron sheets arranged in a side-by-side relationship. 